By Michael Medved

The worst part of the GOP Presidential debate in Houston involved its disproportionate focus on illegal immigration.

The CNN moderators began with that topic and stayed with it for more than a third of the debate’s running time. You’d think that the flow of unauthorized migrants represented the public’s top concern &#8212 but no poll has ever shown that to be the case. Even in Nevada, where Donald Trump won by a landslide, only 20 percent of Republican caucus-goers listed immigration as their big issue.

Related: Why do we choose the leaders we hate most?

This reflects the fact that the flow of illegals across our Southern border has declined sharply since 2007 &#8212 thanks largely to security enhancements by President George W. Bush.

In very conservative South Carolina, 53 percent of Republican voters in the recent primary supported a path to citizenship &#8212 not just legal status &#8212 for undocumented immigrants. The relentless arguments over immigration make Republicans sound strident &#8212 and out of touch with the deeper worries of the public at large.